Cushioning device for presses



p 1930- F. J. RODE 1,774,614

CUSHIONING DEVICE FOR PRESSES Filed March 6, 1929 2 Sheets Sheet l Sept. 2, 1930. F. J. RODE 1 1,774,614

CUSHIONING DEVICE FOR PRESSES I Filed March 6, 1929 2 Shoots-Sheet 2 Patented Sept. 2, 1930 PATENT OFFICE- FRIEDRICH J". ROBE, OF CHICAGO, ILLINOIS 'C'U'SHIONING DEVICE IEQR PRESSES Application filed. March 6, 19529.

This invention relates to improvements in cushioning devices, particularly adapted, though not necessarily limited in its use, with presses for shaping or drawing sheet metal in which the movement of one of the work holding elements will be yieldingly resisted in its movement in one direction by said cushioning device, and one of the objects of the invention is to provide an improved device of this character by means of which the desired or necessary resistance pressure may be obtained, and improved means whereby such pressure may be varied.

A further object is to provide an improved cushioning device of this character which may be incorporated in the press to form an integral part thereof.

To the attainment of these ends and the accomplishment of other new and useful objects as will appear, the invention consists in the features of novelty in substantially the construction, combination and arrangement of the several parts hereinafter more fully described and claimed and shown in the accompanying drawings illustrating this invention and in which Figure 1 is a view partly in elevation, partly in vertical section, and with parts broken away. of a portion of a press having a cushioning device constructed in accordance with the principles of this invention applied thereto.

Figure 2 is a view similar to Figure 1, showing the parts in different positions.

Referring more particularly to the drawings the numeral 10 designates the base of a press, 11 a bolster plate mounted upon the base, 12 a die mounted upon the bolster plate,

13 a work holding element which is supported 49 by pins 14 that pass loosely through the bolster plate, 15 a pressure pad upon which the pins 14 rest, and 16 designates a reciprocable I die member which cooperates with the die 12 and the work holding element 13. The work 17 is gripped between the die 16 and the work holding element 13 to be formed by the dies 12 and 16.

All of the above referred to parts are of the ordinary and well known construction.

Supported below the base of the press and Eerial No. $441,835.

formed integral therewith is a cylinder or chamber 18 which may be of any desired size and configuration and arranged within the chamber or cylinder 18 is another chamber or cylinder '19 of an external diameter considerably less than the internal diameter of the chamber or cylinder 18. Within the cylinder 19 is arranged a piston 20, the piston rod 21 of which is connected in any suitable manner such as by means of intermediate connections 22 with the pressure pad 15 so that when the pressure pad 15 is depressed the piston 20 will e lowered in the cylinder 19 and the piston operating upon the liquid in the cylinder 19. will yieldingly resist the movement of the pad 18 in one direction.

The cylinder 19 is provided with a plurality of openings 23 preferably in the bottom thereof which form communication between the cylinder 19 and the cylinder 18 and these openings 23 are closed by means of a valve 24: arranged in the cylinder 19 and the valve 2 1 encompasses a tubular projection 25 which extends into the cylinder 19.

lhe valve 24 operates to permit liquid to flow from the chamber or cylinder 18 into the cylinder 19 and also operates to close said openings to prevent the liquid from flowing from the cylinder 19 back into the cylinder or chamber 18.

Passing through the tubular projection 25 is an opening or passage 26 which has communication with the chamber or cylinder 18 preferably by means of suitable openings 27 preferably arranged beneath the cylinder 19. Within the opening 16- is arranged a valve casing 28 within which a valve 29 operates. The casing 28 is provided with openings 30 adapted to be closed by the valve 29 so as to open and close communication between the cylinder 19 and the cylinder or chamber 18 through the opening 26, the valve 29 operating in a manner to normally prevent the liquid from flowing from the cylinder or chamber 18 into the cylinder 19 through the opening 26 and also operating to permit the liquid to flow from the cylinder 19 through the opening 26 back into the cylinder or chamber 18.

This valve 29 is adapted to be controlled in a manner to obtain a variable resistance pressure, thevalve 29 being held closed by a predetermined pressure and is unseated by the pressure of the piston 20 upon the liquid in the cylinder 19 when such pressure exceeds the pressure by means of which the valve 29 is closed.

Any suitable means may be provided for obtaining the desired pressure for holding the valve 29 closed, such for instance as cylinders 3132, one superposed upon the other and the cylinders being supported preferably by hangers 33. Within the cylinders are respectively arranged pistons 3435 which are connected by means of a piston rod 36 with the valve 29. Fluid under pressure is admitted to the cylinder 32(beneath the piston 35 and such fluid also flows throughan opening 38 in the piston rod 36 into the cylinder 31 beneath the piston 34. The pressure of. the fluid upon the pistons 34 and 35 will hold the valve 29 seated and this pressure may be predetermined in any well known manner.

Openings 3940 are respectively arranged in the ends of the cylinders 31 and 32 above the respective pistons 35-34 to permit air to escape from the upper side of the pistons so as not to retard the movement of the pistons.

Thus it will be seen that the desired pressure upon the fluid in the cylinders 31-32 will establish the pressure against which the valve 29 must be unseated.

When the valve 29 is unseated the liquid will be forced from the cylinder 19 back into the cylinder or chamber 18.

Air under pressure is admitted into the cylinder or chamber 18 above the liquid therein through a pipe or conduit 41 from any suitable source of supply, a pressure regulator 42 and pressure gauge 43 bein arranged in the pipe 41. After the liquid has been forced from the cylinder 19 the air above the liquid in the cylinder or chamber 18 will be compressed and pressure ofthis air upon the liquid will, when the ram starts to ascend, force the liquid back from the cylinder or chamber 18, into the cylinder or chamber 19 through the openings 23 to unseat the valve 24 and thereby raise the piston 20 and with it the pressure pad 15 and work holder 13.

This cushion operates with a predetermined supply of liquid and the supply of liquid may be delivered into the cylinder or chamber 18 through the pipe 41 by means of a filler branch 44 having a funnel 45, a valve 46 being provided in the pipe 44 for closing the same to prevent the escape of the air from the cylinder or chamber 18. v

A gauge 47 may be provided for the cylinder or chamber 18 and a drain or clean-out pipe 48 may also be provided. Obviously a suitable packing 49 may be provided for the valve stem 36 to form a fluid tight oint, and an air outlet 50 may also be provided for chamber or cylinder 18.

With this improved construction it will be manifest that a predetermined resistance pressure may be created by the pressure of the liquid and this pressure may be varied by 'varying the amount of pressure in the cylinders 31 and 32 which holds the valve 29 seated.

The cylinder 19 may be closed by means of a suitable closure 51 secured in position in any suitable manner.

As the pressure pad 15 starts to descend the piston 20 operates against the liquid in the cylinder 19 and in order to obviate any sudden .shock to the mechanism by the first contact of the piston 20 with the liquid, means are provided for relieving this shock and to that end there is provided an opening 52 in the wall of the cylinder 19 and in which opening is arranged a plunger 53. Connected with the plunger 53 is a piston 54 that operates in a cylinder 55, and to this cylinder 55 is supplied fluid under a predetermined pressure, by means of a supply pipe 56 leading from any suitable source of supply.

With this improved construction it will be manifest that the seating of the valve 29 may be so timed or controlled that the pressure of the liquid upon the piston 20 to return the latter may be delayed so that the pressure pad 15 and the work holder 13 will not immediately follow the ram or die 16 when the latter starts on its return movement.

It will also be obvious that any predetermined amount of liquid may be supplied to the cylinders or pistons as well as any predetermined amount of air under pressure.

Openings 28 may be ,provided in the projection 25 and valve casing 28 to prevent the escape of liquid from behind the valve 29 so as not to interfere with the operation of the valve.

While the preferred form of the invention has been herein shown and described, it is to be understood that various changes may be made in the details 03E construction and in the combination and arrangement of the sev eral parts, within the scope of the claims,

without departing from the spirit of this invention.

What is claimed as new is 1. A cushioning device of the character described embodying a closed cylinder adapted to contain air under pressure and a liquid, a second cylinder Within the first said cylinder and of an external diameter considerably less than the internal diameter of the first said cylinder,a pressure pad, a piston movable in the second recited cylinder for resisting the movement of the pad in one direction, a valved passage forming communication between the cylinders, said valve operating to permit liquid to flow into the second cylinder but prevent the liquid from flowing out of the second cylinder, a liquid outlet leading from the second recited cylinder to the first said cylinder and through which theliquid is forced by the piston, and fiuibl controlled variable resistance pressure creating means for controlling said outlet.

2. A cushioning device of the character described embodying a closed cylinder adapted to contain air under pressure and a liquid, a

second cylinder Within the first said cylinderand of an external diameter considerably less than the internal diameter of the first said cylinder, a pressure pad, a piston movable in the second said cylinder for yieldingly resisting the movement of the pad in one direction, a valved passage forming communication between the cylinders, said valve operating to permit liquid to flow into but not out of the second said cylinder, a second passage through which the liquid will be forced from the second to the first said cylinder, a valve for controlling the last said passage, and means for creating a predetermined resistance pressure upon the last said valve to 'close the same and against which pressure the last said valve is adapted to be opened by pressure created upon the piston during its movement in one direction.

3. A cushioning device of the character described embodying'a closed cylinder adapted to contain air under pressure and a liquid, a second cylinder within the first said cylinder and of 'an external diameter considerably less than the internal diameter of the first said cylinder, a pressure pad, a piston movable in the second recited cylinder for resisting the movement of the pad in one direction, a valved passage forming communication between the cylinders, said valve operating to permit liquid to flow into the second cylinder but prevent the liquid from flowing out of the second cylinder, a liquid outlet leading from the second recited cylinder to the first said cylinder and through which the liquid is forced by the piston, fluid controlled variable resistance pressure creating means for controlling said outlet, and means whereby liquid may be supplied to the first said cylinder. I

4. A cushioning device of the character described embodying twoconcentrically arranged cylinders spaced from each other, the outer cylinder being closed and adapted to contain air under pressure and a liquid, a valved communication between the cylinders to permit the liquid to flow from the first to the second said cylinder and prevent its return to the first said cylinder, a variable resistance pressure controlled passage between the-cylinders through which the liquid may be forced from the second to the first said cylinder, a piston reciprocable in the second said cylinder, and a pressure pad resisted in its movement in one direction by the action of the said piston against the liquid in the second said cylinder.

5. A cushioning device of the character described embodying two concentrically arranged cylinders spaced from each other, the outer cylinder being closed and adapted to contain air under pressure and a liquid, a valved communication between the cylinders to permit the liquid to flow from the first to. the second said cylinder and prevent its return to the first said cylinder, a variable resistance pressure controlled passage between the cylinders through which the liquid may be forced from the second to the first said cylinder, means whereby said resistance pres sure may be varied at will, a piston reciprocable in the second said cylinder, and a pressure pad resisted in its movement in one direction by the action of the said piston against the liquid in the second said cylinder.

6. A cushioning device of the character described, embodying two concentrically arranged cylinders spaced from each other, the outer cylinder being closed and adapted to contain air under pressure and a liquid, a valved communication between the cylinders to permit the liquid to flow from the first to the second said cylinder and prevent its return to the first said cylinder, a variable resistance pressure controlled passage between the cylinders through which the liquid may be forced from the second to the first said cylinder, a piston reciprocable in the second said cylinder, a pressure pad resisted in its movement in onedirection by the action of the said piston against the liquid in the second said cylinder, and means whereby air may be forced into the first said cylinder.

7. A cushioning device of the character described embodying two concentrically arranged cylinders spaced from each other, the outer cylinder being closed and adapted to contain air under pressure and a liquid, a valved communication ,between the cylinders to permit the liquid to flow from the first to the second said cylinder and prevent its return to the first said cylinder, a variable resistance pressure controlled passage between the cylinders through which the liquid may be forced from the second to the first said cylinder, a piston reciprocable in the second said cylinder, a pressure pad resisted in its movement in one direction by the action of the said piston against the liquid in the second said cylinder, and means whereby liquid may be supplied to the first said cylinder.

8. A cushioning device of the character described embodying two concentrically arranged cylinders spaced from each other, the outer cylinder adapted to contain air under pressure and a liquid, a valved communication between said cylinders to permit the liquid to flow from the first to the second cylinder and prevent its return to the first said cylinder, a fluid pressure controlled variable resistance pressure creating means for permitting the liquid to be forced from the second said cylinder to the first said cylinder when a predetermined pressure has been created upon the liquid in the second said cylinder, and a piston element reciprocable in the second said cylinder for creating the last said predetermined resistance pressure under certain conditions.

9. A cushioning device of the character described embodying two concentrically arranged cylinders spaced from each other, the outer cylinder adapted to contain air under pressure and a predetermined supply of liquid, means whereby air may be, forced into the first said cylinder, a valved communication between said cylinders to permit the liquid to flow from the first to the second cylinder and prevent its return to the first said cylinder, a fluid pressure controlled variable resistance pressure creating means for permitting the liquid to be forced from the second said cylinder to the first said cylinder when a predetermined pressure has been created upon the liquid in the second said cylinder, and a piston element reciprocable in the second said cylinder for creating the last said predetermined resistance pressure under certain conditions.

10. A cushioning device of the character described embodying two concentrically arranged cylinders spaced from each other, the outer cylinder being closed and adapted to contain air under pressure and a liquid, a

. valved communication between the cylinders to permit the liquid to flow from the first to the second said cylinder and prevent its return to the first said cylinder, a variable resistance pressure controlled passage between the cylinders through which the liquid may be forced from the second to the first said cylinder, a piston reciprocable in the second said cylinder, a pressure pad resisted in its movement in one direction by the action of the said piston against the liquid in the second said cylinder, and means operating to .utomatically increase the internal area of the second said cylinder at the commencement of the operation of said piston against the pressure of the liquid in the second said cylinder.

11. A cushioning device of the character described embodying two concentrically ar ranged cylinders spaced from each other, the outer cylinder being closed and adapted to contain air under pressure and a liquid, 9.

valved communication between the cylinders to permit the liquid to flow from the first to the second cylinder and prevent its return to the first said cylinder, a variable resistance pressure controlled passage between the cylinders through which the liquid may be forced from the second to the first said cylinder, a piston reciprocable in the second said cylinder, a pressure pad resisted in its movement in one direction by the action of the said piston against the liquid in the second said cylinder, and fluid pressure controlled means operating to automatically increase the internal area of the second said cylinder at the commencement of the operation of the piston against the fluid therein.

12. A cushioning device of the character described embodying a closed cylinder adapted to contain air under pressure and a liquid, a second cylinder within the first said cylinder and of an external diameter considerably less than the internal diameter of the first said cylinder, a pressure pad, a piston movable in the second recited cylinder for resistin'g the novement of the pad in one direction, a valved passage forming communication between the cylinders, said valve operating to permit the liquid to flow into the second cylinder but prevent the liquid from flowing out of the second cylinder, a liquid outlet leading from the second recited cylinder to the first said cylinder and through which the liquid is forced by said piston, and variable resistance pressure creating means for controlling said outlet, said cylinders forming a part and parcel of the press structure.

In testimony whereof I have signed my name to this specification, on this 20th day of February, A. D. 1929.-

FREDRICH J. RODE. 

